/*
 * Copyright (c) 2006, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

package com.sun.source.tree;

/**
 * Provides methods to convert between character positions and line numbers
 * for a compilation unit.
 *
 * @since 1.6
 */
@jdk.Exported
public interface LineMap {

  /**
   * Find the start position of a line.
   *
   * @param line line number (beginning at 1)
   * @return position of first character in line
   * @throws IndexOutOfBoundsException if {@code lineNumber < 1} if {@code lineNumber > no. of
   * lines}
   */
  long getStartPosition(long line);

  /**
   * Find the position corresponding to a (line,column).
   *
   * @param line line number (beginning at 1)
   * @param column tab-expanded column number (beginning 1)
   * @return position of character
   * @throws IndexOutOfBoundsException if {@code line < 1} if {@code line > no. of lines}
   */
  long getPosition(long line, long column);

  /**
   * Find the line containing a position; a line termination
   * character is on the line it terminates.
   *
   * @param pos character offset of the position
   * @return the line number of pos (first line is 1)
   */
  long getLineNumber(long pos);

  /**
   * Find the column for a character position.
   * Tab characters preceding the position on the same line
   * will be expanded when calculating the column number.
   *
   * @param pos character offset of the position
   * @return the tab-expanded column number of pos (first column is 1)
   */
  long getColumnNumber(long pos);

}
